In the past, in a machine tool where a tool attached to a rotary spindle is moved relative to a workpiece so as to work the workpiece, a system designed to suppress the chatter vibration which occurs during the machining operation has been known (for example see Patent Literature 1). The system described in this Patent Literature 1 uses an FFT processing unit to perform Fourier analysis of the vibration acceleration, compares each maximum acceleration calculated by the Fourier analysis with a preset reference value, and decides that chatter vibration to be suppressed has occurred when any single maximum acceleration exceeds the reference value.
Japanese Unexamined Patent Publication No. 2008-290164 A1